• Title/Summary/Keyword: case-controlled study

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Experimental study of solid fuel ignition in a confined enclosure (밀폐공간내 복사에 의한 고체연료 점화의 실험적 연구)

  • Kim, Yeong-Gwan;Baek, Seung-Uk
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.20 no.11
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    • pp.3630-3638
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    • 1996
  • An experimental study has been conducted to explore the behaviors of the radiative ignition of polymethylmetacrylate(PMMA) in a confined enclosure such as the ignition delay time, PMMA surface temperature, the ignition location and the ignition process. In addition, the effects of hot wall orientation on the ignition delay and PMMA surface temperature were studied. When the hot wall is located at the bottom, ignition delay time is the shortest. Ignition surface temperature becomes the lowest for the hot top wall case. These are due to buoyancy effect. Since the radiative heat flux of hot wall is rather lower than laser source, the ignition is considered to be controlled by the mixing process. Therefore, the ignition location, where appropriate mixture of fuel and oxygen exists, occurs near the hot wall. The flame propagates along the hot wall where there exists sufficient oxygen.

Actively controlled sound field of upper sections attached to noise harriers (방음벽 상단 소음의 회절에 관한 능동제어)

  • Koh, Hyo-In;Moser, Michael
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.11a
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    • pp.482-485
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    • 2004
  • On the basis of theoretical studies on the effect of the cylinders attached to semi-infinite screens, the tangential sound power-transport parallel to the surface of the attached cylinder is minimized by means of a secondary sound field, which is generated from a part of the attached cylinder. The numerical study shows the possibility of deflecting the incident sound by minimizing the acoustic surface impedance of the upper sections. The acoustical shadow region was more pronounced in both near- and far-field compared to the passive case with rigid surface, i.e. without active control. For a relatively wide frequency range it was possible to enhance shielding effects only with few secondary sources and error microphones. In this paper effects of some control parameters on the actively controlled sound field near the top edge of noise barriers are studied. Results of numerical study and model measurements are shown and discussed.

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A Review Study of Scalp Acupuncture for Parkinson's Disease in China (중국에서의 파킨슨병 두침치료 임상연구 논문분석)

  • Kim, Woo-Kyung;Kim, Lak-Hyung;Jang, In-Soo
    • Journal of Oriental Neuropsychiatry
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    • v.22 no.4
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    • pp.11-20
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    • 2011
  • Objectives : The purpose of this study was to obtain some knowledge about the scalp acupuncture treatment on Parkinson's disease for the future practice and the research from the clinical studies in China. Methods : The literatures were searched using the database-China Academic Journals(CAJ) (2006-2011). Clinical studies of scalp acupuncture for Parkinson's disease-Randomized controlled trial(RCT), case control study, case series, case report- were included. Results : Of 65 articles, 12 Clinical studies met our inclusion criteria. Three case series reported a significant improvement in the patients with Parkinson's disease by scalp acupuncture, and 9 RCTs reported a significant effectiveness of scalp acupuncture as a monotherapy or as a combination therapy with Madopa Tablet(Levodopa + Benserazide HCl) treatment. Conclusions : The results of this study could be used for the future study about scalp acupuncture for Parkinson's disease.

A Case Report of Soeumbyeong Acne Vulgaris Patient Treated with Osuyu-tang (Wuzhuyu-tang, 吳茱萸湯) (오수유탕(吳茱萸湯)으로 호전된 소음병(少陰病) 여드름 1례)

  • Shin, Jung-min;Hyun, Jun-yeong
    • 대한상한금궤의학회지
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    • v.5 no.1
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    • pp.93-100
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    • 2013
  • Objective : This study aims to explain the effect of Osuyu-tang on an acne vulgaris which a Soeumbyeong patient has. Methods : This is a case report on a female patient who has been suffering from acne vulgaris which is not controlled by normal dermatological treatments. According to Diagnostic system based on Shanghanlun provisions, Osuyu-tang was provided for fifty days. Results : After a series of Osuyu-tang treatments, the patient's symptoms and result of KAGS improved. Conclusions : This case study showed an effectiveness of using Osuyu-tang according to Diagnostic system based on Shanghanlun provisions on acne.

A Study on the Evaluation of Lighting Energy Consumption by Control Strategy of the Electric Lighting (전기조명 제어 전략에 따른 조명에너지 소비량 평가에 관한 연구)

  • Yun, Gyeong;Kim, Kang-Soo
    • KIEAE Journal
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    • v.12 no.1
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    • pp.119-125
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    • 2012
  • The objective of this study is to evaluate the electric lighting energy consumption carried out by Daysim program. A comparison between the measurement and simulated exterior global horizontal illuminance shows differences about 10% and it is very similar to the measurement. The interior illuminance simulated by Daysim are 18.9% lower than the measurement and simulated lighting energy consumption is 10% lower than the measurement. Corrected annual lighting energy simulation results show that the best case is the combination of occupancy switch-off and dimming system with automatic controlled blinds (E-3). In case of no blinds, it occasionally derives the minimum lighting energy consumption but it causes the glare, so we need to be careful for choosing the control strategy. For the overcast sky, the lighting energy consumption is not changed significantly by control strategy while the lighting energy in the clear sky is changed noticeably. So we must know the right strategy for each case to control the electric lights and blinds.

Lifestyle factors related to glucose control for diabetes management strategies: Nested case control design using KNHANES data (당뇨병 관리전략을 위한 혈당조절 관련 생활습관 요인: 국민건강영양조사 활용 코호트내 환자-대조군 연구)

  • Kim, Yunjung;Cho, Eunhee
    • Journal of the Korea Convergence Society
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    • v.10 no.11
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    • pp.501-510
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    • 2019
  • This study aimed to find health related lifestyle factors that influence glycemic control for diabetes mellitus (DM) management strategies. This study used nested case-control design with matching variables that were not controlled by individuals such as age, sex, insulin or oral hypoglycemic agent (OHA) use, disease duration, education level and household income. This study analyzed 983 subjects with type 2 DM who enrolled in the $7^{th}$ (2016-2017) Korean National Health and Nutrition Examination Survey (KNHANES). The target HbA1c level of controlled glucose was defined as less than 6.5%, and 289 (30%) were achieved. Conditional multivariable logistic regression analysis was performed to find self-control factors associated with HbA1c levels. The results statistically significant for variables such as duration of diabetes, insulin or OHA use in overall cohort and body mass index (BMI), smoking and fundus Examination in matched cohort. These results are expected to provide as evidence for the intensive care criteria(disease duration, drug use) and lifestyle management strategy(BMI, smoking, fundus examination).

Complex Regional Pain Syndrome Treated with Bee-venom Herbal Acupuncture: A Case Report

  • Kim, Yong-Suk
    • Journal of Acupuncture Research
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    • v.23 no.2
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    • pp.191-195
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    • 2006
  • This article presents a case report of complex regional pain syndrome (CRPS) involving the ankle and foot; the bee-venom herbal acupuncture (BVH) was performed as part of a pain management program. An 46-year-old man presented with CRPS in the left lower extremity that was inadequately controlled with typical oral medication. Sympathetic block the extremity did not provide significant pain relief. However, BVH resulted in significant pain relief and improvement in patient's attitude. This case report showed that BVH may be efficacious in treating patients with CRPS. Further study is needed to determine the effects of BVH on symptoms related to CRPS.

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Study of Anti-Fading Phenomena during Automotive Braking (자동차 제동시 나타나는 Anti-Fading현상에 관한 연구)

  • Lee, Jung-Ju;Jang, Ho
    • Tribology and Lubricants
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    • v.14 no.1
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    • pp.70-78
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    • 1998
  • Two different friction materials (organic and low-metallic pads) for automotive brakes were studied to investigate the anti-fading phenomena during stop. The anti-fading phenomena were pronounced more in the case of using low metallic friction materials than organic friction materials. The main cause of the anti-fading phenomena was the high dependence of friction coefficient on a sliding speed. The anti-fading was prominent when the initial brake temperature was high in the case of low-metallic friction materials due to the strong stick-slip event at high temperature. On the other hand, the anti-fading was not severe in organic friction materials and the effect was reduced at high braking temperature due to the thermal decomposition of organic friction materials. The strong stickslip phenomena of low metallic friction materials at high temperature induced high torque oscillations during drag test. During this experiment two different braking control modes (pressure controlled and torque controlled modes) were compared. The type of the control mode used for brake test significantly affected the friction characteristics.

Study for the Actuation of Lifter by the Bi-Directional Pump and Single-Rod Cylinder (양방향펌프와 편로드실린더에 의한 리프터의 구동에 관한 연구)

  • Lee, Seong-Rae;Kim, Je-Min
    • Transactions of the Korean Society of Automotive Engineers
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    • v.15 no.4
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    • pp.139-145
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    • 2007
  • The motion of single-rod cylinder is typically controlled by the directional control valve. In some case, the hydraulic system should be energized by the man power and at the same time the motion of a cylinder is controlled manually. It may be confusing for a man to do two things at the same time. The solution is to make up the closed hydraulic circuit with the bi-directional pump and single-rod cylinder without using a directional control valve. In the case of single-rod cylinder, the flows at the rod side and head side are so different that several valves should be installed to make the motion of single-rod cylinder possible. The hydraulic system is composed of a bi-directional pump, a single-rod cylinder, pilot operated check valves, a check valve and a counter balance valve for the purpose of actuating the lifter. The characteristics of a suggested system are analysized mathematically and numerically.

Case-Controlled Study of Bone Mineral Density after Herbal Medicine Intake on Women living in Hong Cheon County, Gangwondo, S. Korea (일부지역여성의 한약투여후 골밀도변화에 대한 환자-대조군 연구 - 강원도 홍천군지역을 중심으로 -)

  • Cha, Yun-Yeob;Park, Hae-Mo;Kim, Yong-Ki;Kim, Gae-Suk;Lee, Sun-Dong
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.21 no.1
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    • pp.322-327
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    • 2007
  • The purpose of this study was to investigate the change of female's Bone Mineral Density after taking herbal medicine. We examined age, sex, marriage, alcohol, smoking, and job of 76 female and their life style related with Osteoporosis. Bone Mineral Density was examined after 1 month (one herbal medicine), 2 months (two herbal medicine), and 3 months (three herbal medicine) between Group I (taking pear extract) and Group II (taking herbal medicine). Bone Mineral Density of Group II after 1 month was increased, but insignificant. Bone Mineral Density was not significantly different between the Group I and Group II after 2 and 3 months. In this study, we can conclude that Bone Mineral Density was increased after 1 month of taking herbal medicine. But we had inaccurate results due to limitations of this study: period of test, accuracy of instrument, impossibility of use young antlers of the deer, and etc. More detailed study should be conducted to yield more concrete results.